Microbiology Of Surgical Site Infections Research Articles

Analysis of risk factors for surgical site infection after colorectal surgery: a cross-sectional study in the east of China pre-COVID-19.

The occurrence of surgical site infection (SSI) can prolong the postoperative hospital stay, increase the economic burden of patients, and even endanger their lives. The purpose of this study was to investigate the incidence, risk factors, and microbiology of SSI after colorectal surgery (CRS) and to provide a basis for the prevention and control of SSI. A single-center, prospective, cross-sectional study of adult patients undergoing CRS was conducted from 2010-2019. Univariate and multivariate logistic regression models were used to collect and analyze demographic information, hospital characteristics, and potential perioperative risk factors of SSI. A total of 3,302 eligible patients were included in this study, with 213 cases experiencing SSIs, resulting in an infection rate of 6.45%. Notably, the incidence of SSI decreased from 13.33% in 2010 to 3.56% in 2019 (Ptrend < 0.001). Escherichia coli accounted for the majority of isolated microorganisms (37.09%), with 49 strains exhibiting resistance to one or more antibiotics (35.25%). Multivariate analysis showed that diabetes, anastomosis leakage, wound classification (contaminated/dirty), operation duration, blood loss greater than 200 ml, and NNIS risk index score for 2 or 3 were independent risk factors. Conversely, laparoscopic approach, preoperative bowel preparation and preoperative albumin levels emerged as protective factors against SSI after CRS. Furthermore, compared to non-SSI patients, SSI patients had a significantly higher 30-day mortality rate following surgery (0.23% vs. 2.35%, p < 0.05). SSI after CRS was susceptible to many factors, and the pathogen of SSI was mainly Escherichia coli. In clinical practice, measures such as correcting preoperative hypoproteinemia, choosing laparoscopic surgery, preoperative bowel preparation and shortening the duration of surgery should be taken to reduce the incidence of SSI.

Occurrence, risk factors, and microbiology of surgical site infections after total knee arthroplasty: preliminary results of a retrospective study.

Occurrence, risk factors, and microbiology of surgical site infections after total knee arthroplasty: preliminary results of a retrospective study.

Microbiology of surgical site infections (SSIs) following skin cancer surgery.

Surgical site infections (SSIs) represent one of the most common and potentially preventable sources of morbidity and healthcare cost escalation associated with skin cancer surgery. There is a lack of data reporting organisms cultured from SSIs in skin surgery, with guidelines for antibiotic prophylaxis based on common skin pathogens rather than actual cultured organisms. In this study, we sought to define the cultured microbiology of SSIs specific to skin cancer surgery and test these against empiric treatment guidelines. All consenting patients presenting to the Auckland regional skin cancer treatment centre over a 6-month period were included. Patients receiving any form of antibiotics within a week prior to surgery were excluded. All wounds were assessed postoperatively, with clinically significant infections identified as those with a standardized wound infection score of 4 (range 0-7) and/or prescribed post-operative antibiotics within 3 weeks of surgery. Wound cultures were recorded. About 104 clinically significant SSIs were identified from 333 lesions treated, with cultures available in 27%. Cultured organisms included MSSA (79%), MRSA (14%), coagulase-negative Staphylococci (11%), and 'skin flora' (14%). Empiric guidelines inaccurately predicted effective treatment in 14% of cases, exclusively due to MRSA. To our knowledge this is the first comprehensive report of SSI microbiology following skin cancer surgery. The overwhelmingly predominant organisms were Staphylococcus sp. (76%), with the rate of MRSA approaching prevalence warranting empiric first-line treatment. These data help inform effective rationalized empiric antibiotic treatment, when indicated, for optimal outcome following skin surgery.

Incidence and Microbiology of Surgical Site Infection Following Hysterectomy at a South African Quaternary Hospital

Incidence and Microbiology of Surgical Site Infection Following Hysterectomy at a South African Quaternary Hospital

Microbiology of surgical site infection in closed upper limb fractures: Data from a prospective trauma registry.

The current study aims to determine the rate of surgical site infection, causal microorganism, and antibiotic sensitivity pattern in operated upper limb closed fractures at the Aga Khan University Hospital, Karachi. Cases presenting between June 2015 to October 2019, were selected from a single-centre, longitudinal, prospective orthopaedic trauma registry. Infection rate, causal microorganism, and antibiotic sensitivity pattern were determined up to six months after surgery. From among a total of 376 closed fractures, 12 encountered surgical site infection with some having late onset, giving an infection rate of 3% which is 1% higher than the international benchmark. Microorganism culture was performed on 5 (42%) patients out of which 2 (40%) were positive. Frequently used prophylactic antibiotics were first generation Cephalosporin and Co-amoxiclav in 9 (75%) patients, but all other patients required other antibiotic categories. Five patients required implant removal with antibiotic coverage. K-wire insertion required prolonged antibiotic treatment. Most of the cultures were negative in spite of the presence of infection.

Prophylactic Topical Antibiotics in Fracture Repair and Spinal Fusion.

Introduction The objective of this systematic review with meta-analysis is to determine whether prophylactic local antibiotics prevent surgical site infections (SSIs) in instrumented spinal fusions and traumatic fracture repair. A secondary objective is to investigate the effect of vancomycin, a common local antibiotic of choice, on the microbiology of SSIs. Methods An electronic search of PubMed, EMBASE, and Web of Science databases and major orthopedic surgery conferences was conducted to identify studies that (1) were instrumented spinal fusions or fracture repair and (2) had a treatment group that received prophylactic local antibiotics. Both randomized controlled trials (RCTs) and comparative observational studies were included. Meta-analysis was performed separately for randomized and nonrandomized studies with subgroup analysis by study design and antibiotic. Results Our review includes 44 articles (30 instrumented spinal fusions and 14 fracture repairs). Intrawound antibiotics significantly decreased the risk of developing SSIs in RCTs of fracture repair (RR 0.61, 95% CI: 0.40–0.93, I2 = 32.5%) but not RCTs of instrumented spinal fusion. Among observational studies, topical antibiotics significantly reduced the risk of SSIs in instrumented spinal fusions (OR 0.34, 95% CI: 0.27–0.43, I2 = 52.4%) and in fracture repair (OR 0.49, 95% CI: 0.37–0.65, I2 = 43.8%). Vancomycin powder decreased the risk of Gram-positive SSIs (OR 0.37, 95% CI: 0.27–0.51, I2 = 0.0%) and had no effect on Gram-negative SSIs (OR 0.95, 95% CI: 0.62–1.44, I2 = 0.0%). Conclusions Prophylactic intrawound antibiotic administration decreases the risk of SSIs in fracture surgical fixation in randomized studies. Therapeutic efficacy in instrumented spinal fusion was seen in only nonrandomized studies. Vancomycin appears to be an effective agent against Gram-positive pathogens. There is no evidence that local vancomycin powder is associated with an increased risk for Gram-negative infection.

890. Incidence and Microbiology of Surgical Site Infection (SSI) after Breast Surgery

BackgroundSurgical site infection (SSI) after breast surgery is much more common than expected after a clean surgical procedure. Although breast SSIs are primarily Gram-positive; recent literature shows an increase in Gram-negative infections. We assessed the risk factors and microbiology of SSI following breast surgery at our institution.MethodsWe conducted a historical cohort study of all (³ 18 y) females who had surgery from 1/1/2014-3/31/2019 and subsequent SSI within 90 days of the procedure. Two controls, matched for surgery type, were selected per case. Data were collected on demographic and clinical characteristics, surgery type, microbiology and antibiotics. Data were analyzed using the χ 2 test, Student’s t-test and multivariable logistic regression with a forward likelihood ratio algorithm.ResultsAfter excluding patients with limited data, we reviewed 284 charts: 95 of 132 cases and 189 controls. The 90-day incidence of SSI was 3.5 % (132/3755). Cases were younger than controls: 53.9 ± 12.4 years vs. 58.3± 13.7 years, respectively, p=0.02. Controls had more comorbidities: 1.8 ± 1.3 vs. 1.4 ± 0.7,respectively, p=0.001. Tissue expanders were placed in 65 (70%) cases versus 11 (5.8%) controls (p < 0.0001). After controlling for age, BMI, comorbidities and post-operative antibiotics, only tissue expanders were associated with infection (OR=35.1, p< 0.0001, 95% CI: 16.6, 74.0).Microbiological data were available for 84 cases. Gram-positive organisms accounted for 45 (53.6%) infections and Gram-negative organisms accounted for 39 (46.4%) infections. Over 72% of African Americans (p= 0.014), 76.5% of patients with diabetes (p=0.005) and 57.1 % with tissue expanders (p= 0.02) had Gram-negative infections. The table shows the multivariable predictors of Gram-negative infection. Tissue expander removal was required in 61.5% of patients with Gram-negative infections compared to 39% with Gram-positive infections.Predictors of Gram-negative SSI after breast surgery ConclusionPatients with tissue expanders had a higher incidence of SSI after breast surgery; removal was often required in Gram-negative infections. Diabetes and post-operative antibiotics were significant predictors of Gram-negative infection. Knowledge of local epidemiology is a key factor in deciding empiric therapy for SSI.Disclosures All Authors: No reported disclosures

2021 Young Investigator Award Winner: Anatomic Gradients in the Microbiology of Spinal Fusion Surgical Site Infection and Resistance to Surgical Antimicrobial Prophylaxis.

Retrospective hospital-registry study. To characterize the microbial epidemiology of surgical site infection (SSI) in spinal fusion surgery and the burden of resistance to standard surgical antibiotic prophylaxis. SSI persists as a leading complication of spinal fusion surgery despite the growth of enhanced recovery programs and improvements in other measures of surgical quality. Improved understandings of SSI microbiology and common mechanisms of failure for current prevention strategies are required to inform the development of novel approaches to prevention relevant to modern surgical practice. Spinal fusion cases performed at a single referral center between January 2011 and June 2019 were reviewed and SSI cases meeting National Healthcare Safety Network criteria were identified. Using microbiologic and procedural data from each case, we analyzed the anatomic distribution of pathogens, their differential time to presentation, and correlation with methicillin-resistant Staphylococcus aureus screening results. Susceptibility of isolates cultured from each infection were compared with the spectrum of surgical antibiotic prophylaxis administered during the index procedure on a per-case basis. Susceptibility to alternate prophylactic agents was also modeled. Among 6727 cases, 351 infections occurred within 90 days. An anatomic gradient in the microbiology of SSI was observed across the length of the back, transitioning from cutaneous (gram-positive) flora in the cervical spine to enteric (gram-negative/anaerobic) flora in the lumbosacral region (correlation coefficient 0.94, P < 0.001). The majority (57.5%) of infections were resistant to the prophylaxis administered during the procedure. Cephalosporin-resistant gram-negative infection was common at lumbosacral levels and undetected methicillin-resistance was common at cervical levels. Individualized infection prevention strategies tailored to operative level are needed in spine surgery. Endogenous wound contamination with enteric flora may be a common mechanism of infection in lumbosacral fusion. Novel approaches to prophylaxis and prevention should be prioritized in this population.Level of Evidence: 3.

Microbiology of surgical site infections in gynecologic oncology population

Microbiology of surgical site infections in gynecologic oncology population

Microbiology of surgical site infections in patients with cancer: A 7-year review

Health care-associated infections (HAIs) have arisen as major sources of multidrug-resistant bacteria. Surgical site infections (SSIs) are the most frequent HAIs in many countries, with high antimicrobial-resistant prevalence. A 7-year retrospective review (2008-2014) of microbiologic data within a prospective surveillance program on patients with SSI at a cancer hospital in Mexico. There were 23,421 surgeries performed during the study period. The SSI rate was 7.9%. Gram-negative bacilli (GNB) were found in 56.5% of samples. Escherichia coli was the most frequent microorganism (27.5%), followed by Staphylococcus aureus (16.3%). SSI caused by S aureus showed a decreasing trend (P = .04). Extended-spectrum β-lactamase (ESBL)-producing E coli increased from 39.5% in 2008 to 72.5% in 2014 (P < .001). Fluoroquinolone resistance also increased in all members of the Enterobacteriaceae. Methicillin-resistant S aureus (MRSA) was isolated in 32% of cases with no significant increase (P value is not significant). GNB caused most SSIs, with an increase of ESBL E coli strains. In breast and thoracic surgery, S aureus remained the most frequent isolate. MRSA remained stable throughout the study period. We observed a decreasing trend in S aureus. These findings show the differences in the microbiology of SSIs in a middle-income country and the increasing trend of ESBL enterobacteria and other multidrug-resistant organisms, such as Enterococcus faecium.

Microbiology of Surgical Site Infections in Cancer Patients: A Seven Year Review

Microbiology of Surgical Site Infections in Cancer Patients: A Seven Year Review

Surgical site infection in critically ill patients with secondary and tertiary peritonitis: epidemiology, microbiology and influence in outcomes.

BackgroundSurgical site infection (SSI) remains a significant problem in the postoperative period that can negatively affect clinical outcomes. Microbiology findings are typically similar to other nosocomial infections, with differences dependent on microbiology selection due to antibiotic pressure or the resident flora. However, this is poorly understood in the critical care setting. We therefore aimed to assess the incidence, epidemiology and microbiology of SSI and its association with outcomes in patients with severe peritonitis in the intensive care unit (ICU).MethodsWe prospectively studied 305 consecutive patients admitted to our surgical ICU from 2010 to 2014 with a diagnosis of secondary or tertiary peritonitis. We collected the following data: SSI diagnosis, demographics, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Simplified Acute Physiology Score (SAPS) II score, type of surgery, microbiology, antibiotic treatment and outcomes. Microbiological sampling was done by means of swabs.ResultsWe identified 269 episodes of SSI in 162 patients (53.1 %) aged 64.4 ± 14.3 years, of which 200 episodes occurred in men (64.6 %). The mean APACHE II and SAPS II scores were 19.7 ± 7.8 and 36.5 ± 16.1 respectively. The mean ICU and hospital stays were 19.8 ± 24.8 and 21.7 ± 30 days respectively. Pseudomonas spp. (n = 52, 19.3 %), Escherichia coli (n = 55, 20.4 %) and Candida spp. (n = 46, 17.1 %) were the most frequently isolated microorganisms, but gram-positive cocci (n = 80, 29.7 %) were also frequent. Microorganisms isolated from SSIs were associated with a higher incidence of antibiotic resistance (64.9 %) in ICU patients, but not with higher in-hospital mortality. However, patients who suffered from SSI had longer ICU admissions (odds ratio = 1.024, 95 % confidence interval 1.010–1.039, P = 0.001).ConclusionsThe incidence of SSI in secondary or tertiary peritonitis requiring ICU admission is very high. Physicians may consider antibiotic-resistant pathogens, gram-positive cocci and fungi when choosing empiric antibiotic treatment for SSI, although more studies are needed to confirm our results due to the inherent limitations of the microbiological sampling with swabs performed in our research. The presence of SSI may be associated with prolonged ICU stays, but without any influence on overall mortality.

Incidence and microbiology of surgical site infections following coronary artery bypass graft (CABG) surgery at a tertiary care hospital in Jaipur, India

Incidence and microbiology of surgical site infections following coronary artery bypass graft (CABG) surgery at a tertiary care hospital in Jaipur, India

The time course and microbiology of surgical site infections after head and neck free flap surgery.

Determine the time of onset and microbiology of surgical site infections (SSIs) following head and neck free flap reconstructive surgeries. Retrospective cohort study. All 504 free flap surgical cases (484 patients) performed April 1, 2009 to September 30, 2013 were reviewed; SSIs occurring ≤30 days postoperatively were evaluated. Admission screening for methicillin-resistant Staphylococcus aureus (MRSA) colonization was performed on all patients. Flap-recipient site infections (flap SSIs) occurred in 67 cases (13.3%), one-third week 1 postoperatively, one-third week 2, one-third days 15 to 30; 45% occurred after hospital discharge. Wound cultures were polymicrobial, but 25% grew only normal oral flora, whereas 75% grew pathogens not part of normal oral flora, such as gram-negative bacilli (44% of cases), MRSA (20%), and methicillin-sensitive S aureus (MSSA) (16%). The frequency of these pathogens did not vary significantly by the time of SSI onset. In 67%, cultures included at least one pathogen resistant to the prophylactic antibiotic used. Clindamycin prophylaxis was a significant risk factor for flap SSI and for early partial or complete flap loss from infection. Donor SSIs occurred in 22 cases (4.4%), 95% >1 week postoperatively, and MRSA or MSSA were the primary pathogens in 89%. Of the 25 patients colonized with MRSA on admission, 40% developed a flap or donor SSI, a rate significantly higher than in non-colonized patients. Gram-negative bacilli, MRSA, and MSSA were significant SSI pathogens, and late onset of infection was common. Better screening, decolonization, and prophylaxis may reduce SSI rates. 2b

Current Microbiology of Surgical Site Infections in Patients with Cancer: A Retrospective Review.

BackgroundPatients with solid tumors frequently undergo surgical procedures and develop procedure-related infections. We sought to describe the current microbiologic spectrum of infections at various sites following common surgical procedures.MethodsThis was a retrospective review of microbiologic data between January 2011 and February 2012. The sites studied were those associated with breast cancer surgery, thoracotomy, craniotomy, percutaneous endoscopic gastrostomy (PEG) tube insertion, and abdominal/pelvic surgery. Only patients with solid tumors were included.ResultsA total of 368 surgical site infections (SSIs) were identified (68 breast cancer related; 91 thoracotomy related; 45 craniotomy related; 75 PEG-tube insertion related; and 89 abdominal/pelvic surgery related). Of these, 58% were monomicrobial and 42% were polymicrobial. Overall, 85% of the 215 monomicrobial infections were caused by Gram-positive organisms and 13% by Gram-negative bacilli (GNB). Staphylococcus aureus was the predominant pathogen in monomicrobial infections (150 of 215, 70%). Sixty (40%) of these staphylococcal isolates were methicillin resistant (MRSA), and 65% had a vancomycin minimal inhibitory concentration (MIC) ≥1.0 µg/ml. Pseudomonas aeruginosa was the predominant GNB pathogen (19 of 27, 70%). Staphylococci were also the predominant pathogens in polymicrobial infections, while P. aeruginosa and Escherichia coli were the predominant GNB. Overall, 35% of isolates from polymicrobial infections were GNB. Cephalosporins (e.g., cefazolin) or amoxicillin/clavulanate was used most often for surgical prophylaxis, and 47% of organisms from monomicrobial infections (MRSA, P. aeruginosa) were resistant to them. A similar resistance pattern was observed in polymicrobial infections.Conclusion Staphylococcus species were isolated most often from the sites studied. Polymicrobial infections (42%) and GNB monomicrobial infections (13%) were relatively frequent causes of SSIs. Many of these infections were caused by organisms that are resistant to agents commonly used for surgical prophylaxis. Additionally, 65% of staphylococcal isolates had a vancomycin MIC ≥1.0 µg/ml, suggesting the need for alternative therapeutic agents.Electronic supplementary materialThe online version of this article (doi:10.1007/s40121-014-0048-4) contains supplementary material, which is available to authorized users.

Microbiology of Surgical Site Infections after Gastrointestinal Surgery in the South Region of The Netherlands

To give an overview of the microbiology of blood and wound samples from surgical site infections (SSIs) after gastrointestinal surgery, as well as the antimicrobial susceptibility of the microorganisms involved, and to discuss the appropriateness of the prophylactic antibiotics administered. During a 3.5-year study period, wound swabs and blood samples of patients with an SSI were taken in the first 48 h after surgery until 30 days thereafter. Most pathogens were isolated from wound swabs. Escherichia coli (25%) and Pseudomonas aeruginosa (10%) were the most frequently found microorganisms. Both microorganisms showed a slight tendency towards a decrease in susceptibility for the tested antibiotics, although after correction, this was not significant. The comparison between wound swabs taken in the first 48 h after a surgical procedure and swabs in the 30 days thereafter provides important information concerning the microbiology of SSIs and the development of antibiotic resistance of the causative agents over time.

Surgical Site Infections in Spine Surgery

Retrospective analysis. The objective of this study was to describe the microbiology of surgical site infection (SSI) in spine surgery and relationship with surgical management characteristics. SSI is an important complication of spine surgery that results in significant morbidity. A comprehensive and contemporary understanding of the microbiology of postoperative spine infections is valuable to direct empiric antimicrobial treatment and prophylaxis and other infection prevention strategies. All cases of spinal surgery associated with SSI between July 2005 and November 2010 were identified by the hospital infection control surveillance program using Centers for Disease Control National Health Safety Network criteria. Surgical characteristics and microbiologic data for each case were gathered by direct medical record review. Of 7529 operative spine cases performed between July 2005 and November 2010, 239 cases of SSI were identified. The most commonly isolated pathogen was Staphylococcus aureus (45.2%), followed by Staphylococcus epidermidis (31.4%). Methicillin-resistant organisms accounted for 34.3% of all SSIs and were more common in revision than in primary surgical procedures (47.4% vs. 28.0%, P = 0.003). Gram-negative organisms were identified in 30.5% of the cases. Spine surgical procedures involving the sacrum were significantly associated with gram-negative organisms (P < 0.001) and polymicrobial infections (P = 0.020). Infections due to gram-negative organisms (P = 0.002) and Enterococcus spp. (P = 0.038) were less common in surgical procedures involving the cervical spine. Cefazolin-resistant gram-negative organisms accounted for 61.6% of all gram-negative infections and 18.8% of all SSIs. Although gram-positive organisms predominated, gram-negative organisms accounted for a sizeable portion of SSI, particularly among lower lumbar and sacral spine surgical procedures. Nearly half of infections in revision surgery were due to a methicillin-resistant organism. These findings may help guide choice of empiric antibiotics while awaiting culture data and antimicrobial prophylaxis strategies in specific spine surgical procedures. 3.

Microbiology of Surgical Site Infections in Abdominal Tract Surgery Patients

IntroductionKnowledge of the microbiology of surgical infections after abdominal surgery can be of use when prescribing effective empirical antibiotic treatments. MethodAnalysis of surgical infections after abdominal surgery in patients enrolled in the Prevalence of Infections in Spanish Hospitals (EPINE) corresponding to the years 1999–2006. ResultsDuring the period of the study, 2280 patients who were subjected to upper or lower abdominal tract surgery were diagnosed with an infection at the surgical site (SSI). Eight hundred and eighty-three patients (37%) had an operation of the upper abdominal tract (gastric, hepatobiliary, and pancreatic surgery) and 1447 patients (63%) had lower abdominal tract surgery (appendectomy and colon surgery). A total of 2617 bacterial species were isolated in the 2280 patients included in the analysis. The most frequent microorganisms isolated were, Escherichia coli (28%), Enterococcus spp. (15%), Streptococcus spp. (8%), Pseudomonas aeruginosa (7%), and Staphylococcus aureus (5%, resistant to methicillin 2%). In the surgical infections after upper abdominal tract procedures, there were a higher proportion of isolations of staphylococci, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp. and Candida albicans and less E. coli, Bacteroides fragilis and Clostridium spp. ConclusionThe microbiology of SSI produced after upper abdominal tract surgery did not show any significant differences compared to those of the lower tract. However, more cases of SSI were detected due to staphylococci, K. pneumoniae, Enterobacter spp., Acinetobacter spp. and C. albicans and less caused by E. coli, B. fragilis and Clostridium spp.

Microbiology of Surgical Site Infections Complicating Breast Surgery

Surgical site infection (SSI) rates complicating breast surgery have ranged from 1-26%, but limited data have been provided regarding pathogen identification and in vitro susceptibility results. The aim of this study was to evaluate the results of bacterial cultures of breast SSI sites and antibiotic susceptibility testing to determine the clinical utility of these findings. Medical records were reviewed for SSI in patients who had undergone breast/axillary surgical procedures between June 2003 and June 2006. An SSI was defined by the criteria of the U.S. Centers for Disease Control and Prevention. Clinical data were collected on perioperative prophylactic antibiotics, organisms isolated, and resistance profiles. A total of 832 breast/axillary operations in 683 patients were included. Material was available for culture in 67/144 SSI (47%), but cultures were obtained from only 41 of these sites (61%). There were 25 sites with positive bacterial cultures from which 35 organisms were isolated. Staphylococci were the organisms isolated most commonly (n = 21; 60%); 14 other isolates (40%) included gram-negative bacilli and anaerobes. Susceptibility testing was performed on 16 (76%) of the staphylococcal isolates. Ten (63%) exhibited drug resistance; five were multi-drug resistant. Six of eight non-staphylococcal isolates tested (75%) exhibited antibiotic resistance; two were multi-drug resistant. Although the usual empiric treatment of SSI after breast surgery targets staphylococci, cultures with susceptibility profiles should be obtained because non-staphylococcal bacteria were commonly identified, and drug resistance was seen in more than one-half of the isolates. Further study is needed to define the optimal empiric antibiotic therapy for SSI after breast surgery.

Microbiology of Surgical Site Infections and Associated Antimicrobial Use Among Vietnamese Orthopedic and Neurosurgical Patients

To determine the pathogens associated with surgical site infections (SSIs) and describe patterns of antimicrobial use and resistance in orthopedic and neurosurgical patients in a large university hospital in Vietnam. Prospective cohort study. Cho Ray Hospital, Ho Chi Minh City, Vietnam. All patients who had operations during a 5-week study period. Of 702 surgical patients, 80 (11.4%) developed an SSI. The incidence of SSI among orthopedic patients was 15.2% (48 of 315), and among neurosurgical patients it was 8.3% (32 of 387). Postoperative bacterial cultures of samples from the surgical sites were performed for 55 (68.8%) of the 80 patients with SSI; 68 wound swab specimens and 10 cerebrospinal fluid samples were cultured. Of these 78 cultures, 60 (76.9%) were positive for a pathogen, and 15 (25%) of those 60 cultures yielded multiple pathogens. The 3 most frequently isolated pathogens were Pseudomonas aeruginosa (29.5% of isolates), Staphylococcus aureus (11.5% of isolates), and Escherichia coli (10.3% of isolates). Ninety percent of S. aureus isolates were methicillin resistant, 91% of P. aeruginosa isolates were ceftazidime resistant, and 38% of E. coli isolates were cefotaxime resistant. All but 1 of the 702 patients received antimicrobial therapy after surgery, and the median duration of antimicrobial therapy was 11 days. Commonly used antimicrobials included aminopenicillins and second- and third-generation cephalosporins. Two or more agents were given to 634 (90%) of the patients, and most combination drug regimens (86%) included an aminoglycoside. Our data indicate that the incidence of SSI is high in our study population, that the main pathogens causing SSI are gram-negative bacteria and are often resistant to commonly used antimicrobials, that the use of broad-spectrum antimicrobials after surgery is widespread, and that implementation of interventions aimed at promoting appropriate and evidence-based use of antimicrobials are needed in Vietnam.